Abstract: An ejection apparatus for ejecting material from a liquid at a plurality of ejection locations (4) disposed in a row, has a plurality of channels (11) through each of which liquid flows in use to or from a respective ejection location at an open end of the channel. An ejection electrode (7) is disposed at each ejection location by means of which an electric field is created in use to cause the ejection of material from the liquid. An electrically conductive path (12) exists to each ejection electrode for supplying a voltage to the ejection electrode (7) in use. The channels (11) are isolated from one another and the electrically conductive paths (12) are separated from the channels over substantially the whole of their length.

Abstract: A printhead (1) for an ink jet printer includes a chamber (5) for containing marking fluid fed to the head in use. A plurality of orifices (8) open from the chamber (5), a marking fluid being emitted in use through the orifices (8). A corresponding plurality of actuators are provided. Each actuator comprises an arm (12) having at one end means for selectively opening and closing a respective orifice (8); a magnetic circuit (12, 13, 14, 15) of which the arm (12) forms a side; and one or more coils (14) for selectively inducing a magnetic flux in the circuit in order to move the arm (12) between a position in which it closes the respective orifice (8) and a position in which it opens the orifice (8).